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Related papers: Space-Time Graded-Index Interfaces and Related Chi…

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While nonlinear effects in graded-index (GRIN) multimode fibers have been studied extensively, little is known about nonlinear effects in larger GRIN waveguides, where the number of modes approaches infinity and modal dispersion becomes…

The spatial impulse response (SIR) method is a well-known approach to calculate transient acoustic fields of arbitrary-shape transducers. It involves the evaluation of a time-dependent surface integral. Although analytic expressions of the…

Numerical Analysis · Mathematics 2021-11-01 Dimitris Perdios , Florian Martinez , Marcel Arditi , Jean-Philippe Thiran

Multidimensional Index Modulations (IM) are a novel alternative to conventional modulations which can bring considerable benefits for future wireless networks. Within this scope, in this paper we present a new scheme, named as…

Signal Processing · Electrical Eng. & Systems 2021-08-09 Vasco Velez , Joao Pedro Pavia , Nuno Souto , Pedro Sebastiao , Americo Correia

Space-time modulation induced non-reciprocity in EM metasurfaces is proposed and numerically demonstrated using rigorous Generalized Sheet Transitions Conditions (GSTCs) under oblique plane-wave incidence. It is phenomenologically shown…

Optics · Physics 2017-04-03 Shulabh Gupta , Scott. A. Stewart , Tom J. Smy

Sparse sensor placement is a central challenge in the efficient characterization of complex systems when the cost of acquiring and processing data is high. Leading sparse sensing methods typically exploit either spatial or temporal…

Optimization and Control · Mathematics 2022-06-08 Thomas L. Mohren , Thomas L. Daniel , Steven L. Brunton , Bingni W. Brunton

Iterative methods are widely used for solving partial differential equations (PDEs). However, the difficulty in eliminating global low-frequency errors significantly limits their convergence speed. In recent years, neural networks have…

Computational Physics · Physics 2024-10-10 Daiwei Dong , Wei Suo , Jiaqing Kou , Weiwei Zhang

Rendering dynamic reverberation in a complicated acoustic space for moving sources and listeners is challenging but crucial for enhancing user immersion in extended-reality (XR) applications. Capturing spatially varying room impulse…

Audio and Speech Processing · Electrical Eng. & Systems 2026-02-10 Orchisama Das , Gloria Dal Santo , Sebastian J. Schlecht , Vesa Valimaki , Zoran Cvetkovic

We develop improved physics-informed neural networks (PINNs) for high-order and high-dimensional power system models described by nonlinear ordinary differential equations. We propose some novel enhancements to improve PINN training and…

Machine Learning · Computer Science 2024-10-11 Vineet Jagadeesan Nair

An accurate and fast method is presented for scattering of electromagnetic waves from an array of time-modulated graphene ribbons. We derive a time-domain integral equation for induced surface currents under subwavelength approximation.…

Optics · Physics 2023-06-28 Mahdi Rahmanzadeh , Behzad Rejaei , Amin Khavasi

Developing machine intelligence abilities in robots and autonomous systems is an expensive and time consuming process. Existing solutions are tailored to specific applications and are harder to generalize. Furthermore, scarcity of training…

Robotics · Computer Science 2023-10-10 Sai Vemprala , Shuhang Chen , Abhinav Shukla , Dinesh Narayanan , Ashish Kapoor

The use of modern software-defined radio (SDR) devices enables the implementation of efficient communication systems in numerous scenarios. Such technology comes especially handy in the context of search and rescue (SAR) systems, enabling…

Signal Processing · Electrical Eng. & Systems 2023-12-11 Daniel Gil Gaviria , Marcus Müller , Felix Artmann , Laurent Schmalen

We model the effects of cross-phase modulation in frequency (or wavelength) division multiplexed optical communications systems, using a Schr\"odinger equation with a spatially and temporally random potential. Green's functions for the…

Optics · Physics 2009-11-07 A. G. Green , P. B. Littlewood , P. P. Mitra , L. G. L. Wegener

In this article, we propose an index modulation system suitable for optical communications, where the intensity of the light is modulated along the time, space and frequency dimensions, building a Frequency-Hopping Spatial Multi-Pulse…

Information Theory · Computer Science 2020-04-22 Francisco J. Escribano , Alexandre Wagemakers , Georges Kaddoum , Joao V. C. Evangelista

We present an open-source multimode nonlinear Schr\"odinger equation-based simulation to investigate spatiotemporal nonlinear pulse propagation in thin-film silicon nitride (SiN) waveguides. Using this framework, we analyze femtosecond…

Optics · Physics 2025-08-27 Azka Maula Iskandar Muda , Uğur Teğin

Sequential recommender systems aim to predict a user's future interests by extracting temporal patterns from their behavioral history. Existing approaches typically employ transformer-based architectures to process long sequences of user…

Information Retrieval · Computer Science 2026-02-24 Adamya Shyam , Venkateswara Rao Kagita , Bharti Rana , Vikas Kumar

Space-time wave packets (STWPs) are pulsed fields in which a strictly prescribed association between the spatial and temporal frequencies yields surprising and useful behavior. However, STWPs to date have been synthesized using bulky…

The paper investigates a non-intrusive parallel time integration with multigrid for space-fractional diffusion equations in two spatial dimensions. We firstly obtain a fully discrete scheme via using the linear finite element method to…

Numerical Analysis · Mathematics 2018-05-18 Xiaoqiang Yue , Shi Shu , Xiaowen Xu , Weiping Bu , Kejia Pan

The geometric properties of spacetimes representing expanding impulsive gravitational waves, propagating on a flat background and generated by snapped cosmic strings, are studied. The construction of the line element is reviewed, and…

General Relativity and Quantum Cosmology · Physics 2023-02-24 David Kofron , Michal Karamazov , Robert Svarc

Radiation heat transfer in a graded-index medium often suffers accuracy problems due to the gradual changes in the refractive index. The finite element method, meshfree, and other numerical methods often struggle to maintain accuracy when…

Numerical Analysis · Mathematics 2024-12-25 K. Murari , S. Sundar

Metasurfaces characterized by a transverse gradient of local impedance have recently opened exciting directions for light manipulation at the nanoscale. Here we add a temporal gradient to the picture, showing that spatio-temporal variations…

Mesoscale and Nanoscale Physics · Physics 2015-09-30 Y. Hadad , D. L. Sounas , A. Alu
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